PCR Amplification With Sequence-specific Primers Research Articles

Prevalence of Lewis Blood Group Polymorphisms in Southern Thai Blood Donors

Objective: To determine the frequencies of five of the most common (59T>G, 202T>C, 314C>T, 508G>A and 1067T>G) single nucleotide polymorphisms (SNPs) of the FUT3 gene in Thai blood donors and examine their associations with the presence or absence of Lewis antigens on red blood cells.Material and Methods: A total of 364 donor specimens from Songklanagarind Hospital and Regional Blood Centre XII Songkhla, Thailand, were recruited for the study. Molecular analysis of each SNP was performed by polymerase chain reaction amplification with sequence-specific primers (PCR-SSP). The Lewis phenotype was investigated in 159 individuals using the standard hemagglutination test.Results: The frequencies of the SNPs were 32.0% (59T>G), 46.6% (202T>C), 21.7% (314C>T), 37.9% (508G>A), and 25.0% (1067T>A). The prevalences of the Lewis phenotype were 61.0% for Le(a-b+), 7.6% for Le(a+b-), 11.3% for Le(a+b+), and 20.1% for Le(a-b-). The Lewis-negative phenotype was significantly associated with homozygosity in 59T>G and 1067T>A (χ2 =49.873, and χ2 =44.520, respectively).Conclusion: Our findings suggest that le59,1067 is largely responsible for the Lewis-negative phenotype in our southern Thai population. Genetic variations in FUT3 polymorphisms may be used as molecular markers for ethnicity and to help understand the roles of the Lewis blood group in infections or clinical diseases.

Association between TNF‐α polymorphisms and the risk of upper gastrointestinal bleeding induced by aspirin in patients with coronary heart disease

To investigate the correlation of tumor necrosis factor α (TNF-α) polymorphisms with upper gastrointestinal bleeding (UGIB) induced by enteric-coated aspirin in coronary heart disease (CHD) patients. In total, 154 CHD patients taking enteric-coated aspirin were enrolled in this study. Patients were divided into the UGIB group (n=57) and non-UGIB group (n=97) based on the presence or absence of signs of UGIB, respectively. TNF-α polymorphism (-857C>T, -863C>A, and -1031T>C) genotyping was performed using polymerase chain reaction (PCR) amplification with sequence-specific primers (PCR-SSP). Patients who had the CC genotype and C allele of -1031T>C exhibited a significantly increase risk of UGIB after receiving enteric-coated aspirin (CC vs. TT: odds (OR) (95% confidence interval (CI)): 7.568 (1.527-37.49), P=0.005; C vs. T: OR (95% CI): 1.852 (1.036-3.312), P=0.036). Patients who had CA and CA + AA genotypes and the A allele of -863C>A also exhibited an increased risk of aspirin-induced UGIB (CA vs. CC: OR (95% CI): 2.415 (1.143-5.101), P=0.019: CA + AA vs. CC: OR (95% CI): 2.218 (1.123-4.381), P=0.021; A vs. C: OR (95% CI): 1.788 (1.039-3.078), P=0.035). However, the TNF-α -857 C>T polymorphism was unrelated to the induction of UGIB by enteric-coated aspirin in CHD patients (P>0.05). In addition, the haplotypes of CCC (-1031T>C, -863C>A, and -857C>T) markedly reduced the risk of aspirin-induced UGIB in CHD patients. TNF-α -863A and -1031C increased the risk of UGIB induction by enteric-coated aspirin in CHD patients, whereas TNF-α -857C>T was not correlated with the UGIB risk.

Association Between HLA-A*02 Genotype and Multiple Sclerosis in Khuzestan Province, Iran

Background: Multiple sclerosis (MS) is a chronic, inflammatory, demyelinating, and neurodegenerative autoimmune disease of the central nervous system (CNS). In the disease, the immune system attacks myelin sheath around neurons. The pathogenesis of this disease is still unknown, but there is evidence of complex interactions of both environmental and genetic factors. The recent evidence suggests that HLA class I may also contribute to MS and the negative association and protective role of HLA-A*02 with MS is confirmed. The current study aimed at investigating the association between HLA-A*02 with MS in Khuzestan province, Iran. Methods: The current study was conducted on 200 patients with MS and 200 healthy controls from Khuzestan Province. The male to female ratio was 1:4. HLA typing was performed by polymerase chain reaction (PCR) amplification with sequence-specific primers (PCR-SSP) method. The association between HLA-A*02 and MS was evaluated with SPSS version 21 using chi-square test. Results: The most abundant type of MS in the current study participants was RRMS with the frequency of 87.93%, and the remaining 20% had progressive relapsing (PR), primary progressive (PP), and secondary progressive (SP) MS. There was a significant decrease in the frequency of HLA-A*02 in patients with MS (29%) in comparison with the healthy control (54%) and negative association of HLA-A*02 with MS (P < 0.0001, odds ratio (OR) = 0.356) was observed. The average of EDSS was 1.9 and most of the patients (about 60.5%) had EDSS of 1 - 3. There was no significant statistical association between HLA-A*02 and the variables of gender, ethnicity, EDSS grade, and type of MS in the study participants. Conclusions: According to the current study results, HLA–A*02 genotype decreased the risk of MS and had a protective role against multiple sclerosis in Khuzestan Province.

Polymorphisms of human leukocyte antigen B*27 on clinical phenotype of spondyloarthritis in Chinese.

In recent years, an ever-increasing number of alleles of human leukocyte antigen B*27 (HLA-B*27) have been identified. This study aimed to establish an updated method for HLA-B*27 subtyping, and to investigate the impact of HLA-B*27 polymorphisms on the clinical phenotype of spondyloarthritis (SpA). Overall, 184 SpA patients were recruited for analyzing diversity of HLA-B*27 via an updated high-resolution polymerase chain reaction amplification with sequence specific primers (PCR-SSP). The prevalence of HLA-B*27 was 94.0%, and four subtypes were identified including HLA-B*2704 (77.5%), B*2705 (20.2%), B*2707 (1.7%), and B*2724 (0.6%). There was an obvious male predominance (P=.05) and markedly elevated C-reaction protein (CRP) in B*27 positive SpA (P<.01). In multivariate linear regression analysis, the elevated CRP was positively associated with HLA-B*27 positivity (regression coefficient B=46.1, P=.0003), grade of sacroiliitis (B=47.5, P=.0032), and male gender (B=20.4, P=.0041). Notably, a male predilection was also found in B*2705 positive SpA while B*2707 was associated with older age, higher positive family history, and higher prevalence of extra-articular features (all P<.05). In this study, an updated PCR-SSP technique to identify increasing alleles of HLA-B*27 was developed and their different effects on clinical manifestations of SpA were demonstrated. Genotyping of HLA-B*27 would shed light on our understanding of the pathogenesis of SpA.

Analysis of HLA-DQB1*0602 in Multiple Sclerosis Patients in Khuzestan Province, Iran.

Multiple sclerosis (MS) is a chronic, demyelinating, autoimmune and also complex disease of the central nervous system the etiology of which is not completely defined; but both genetic and environmental factors are regarded as main factors in its susceptibility. HLA-DQB1*0602 is considered as one of the most important genetic factors in MS predisposition but contradictory results have been reported in different populations world-wide. Since there are no data with respect to the correlation of HLA-DQB1*0602 and multiple sclerosis in Khuzestan province, and because of ethnic diversity in Khuzestan province, the aim was to examine the association of this allele with multiple sclerosis in Khuzestan. This is a case control study that evaluated 200 MS patients from Khuzestan and 200 healthy individuals from the same geographical region. DNA extraction was performed by salting out method; in addition, HLA typing was carried out by polymerase chain reaction amplification with sequence-specific primers (PCR-SSP) method. The present study also considered probable association among HLA-DQB1*0602 with sex, ethnicity, and type of disease. Results revealed that distribution of mentioned allele was not statistically different among cases and controls (61.5% vs. 64%, P = 0.605); furthermore, no association was shown between this allele and gender, ethnicity or type of disease. On the whole, our result is consistent with most of the other studies in Iran; but contrasts with most of the studies in European populations.

Association of HLA class II alleles with hepatitis C virus clearance and persistence in thalassemia patients from Iran.

There is no published data on association of HLA class II alleles with clearance or persistence after acute hepatitis C virus (HCV) infection in patients from Iran. HLA DRB1, DQA1, and DQB1 alleles were determined using polymerase chain reaction amplification with sequence specific primers (PCR-SSP) on a total of 117 thalassemia patients (63 with chronic infection, and 54 with viral clearance) and 120 healthy controls. HLA-DRB1*0301 and DQA1*0501 alleles were found significantly present in patients with HCV clearance compared to those with chronic infection (P = 0.03 and P = 0.0007, respectively). By contrast, DRB1*0701, DQA1*0201, and DQB1*0602 alleles occurred significantly in those with chronic infection compared to those with viral clearance (P = 0.004, P = 0.007, and P = 0.02, respectively). As compared to the controls, DRB1*0301, DRB1*11, DQA1*0501, and DQB1*0301 alleles showed a significant decrease in chronic patients (P = 0.002, P = 0.001, P = 0.0001, and P = 0.0004, respectively). Furthermore, the haplotype frequencies of DRB1*0301, DQA1*0501, DQB1*0201, and DRB1*1101, DQA1*0501, DQB1*0301 were found significantly higher (P = 0.004 and P = 0.04, respectively) in patients with HCV clearance than those with chronic infection. By contrast, the haplotype DRB1*0701, DQA1*0201, DQB1*0201 occurred more frequently (P = 0.02) in those with chronic infection compared with those with viral clearance. These findings suggest that particular HLA alleles and related haplotypes may have an influence on the outcome of HCV infection among the Iranian patients. Some of the HLA alleles found in the Iranian patients are different from those reported elsewhere, suggesting that the immunogenetic makeup for HCV clearance or persistence may vary based on the ethnicity.

Mo1023 The Single Nucleotide Polymorphism in the Vitamin D Pathway DHCR7 Gene and Pre-Treatment HBV-DNA Strongly Predict HBeAg Loss in HBeAg-Positive Chronic Hepatitis B Patients Treated With Pegylated Interferon: Multicenter Study

Aim: Clinical outcome after hepatitis B virus (HBV) exposure vary extremely from spontaneous clearance to chronic hepatitis B and often progresses to liver cirrhosis and hepatocellular carcinoma. Host genetic factor plays an important role in the regulation of immune response. The study was designed to investigate whether (HLA) class II DQA1 and DQB1 gene polymorphism are associated with chronic hepatitis B infection and whether it leads to the development of HBV related liver cirrhosis (LC) and hepatocellular carcinoma (HCC) in north Indian population. Methods: We have assessed the DQA1 and DQB1 allele polymorphism in 187 HBV related liver diseases which included (73 chronic hepatitis B, 84 LC, and 30 HCC patients) and 109 controls who had spontaneously recovered from HBV infection by using polymerase chain reaction amplification with sequence specific primers (PCR-SSP). Results: The data suggest that DQA1*0101/2/4 (OR=2.78; P=0.003), DQA1*0103 (OR= 2.64; P=0.0007) and DQB1*0302/3 (OR=2.15; P=0.01) were associated with protection from chronic HBV infection, while DQB1*0402 (OR=0.25; P=0.001) conferred susceptibility to chronic HBV infection, respectively. It was also observed that DQB1*0601 (OR=3.73; P=0.006) conferred protective effect from developing Liver Cirrhosis, similarly DQB1*0302/ 3 (OR=5.53; P=0.05) and DQB1*0402 (OR=0.00; P=0.0001) conferred protective effect from progressing to HCC. Though, DQA1*0601 and DQB1*0503 showed some susceptible effect on chronic HBV infection, these association were no longer significant after Bonferroni correction (P=0.23, P=0.59). Conclusion: The results suggest that various subtypes of HLA-DQA1 and DQB1 does influence the HBV clearance and development of chronic HBV infections in north Indian population.

Associations between HLA-A\B\DRB1 polymorphisms and risks of vulvar lichen sclerosus or squamous cell hyperplasia of the vulva.

In this study, we aimed to explore the associations between HLA-A\B\DRB1 polymorphisms and the risks of vulvar lichen sclerosus (VLS) or squamous cell hyperplasia of the vulva (SCHV) in Han Chinese women. We enrolled 76 Han Chinese women with VLS (Group A), 74 with SCHV (Group B), and 66 healthy women (control group) in this study. Polymerase chain reaction amplification with sequence specific primers (PCR-SSP) was used to determine HLA-A\B\DRB1 polymorphisms. Compared with the control group, HLA-A*11, -B*15, and -DRB1*12 were present at a higher frequency in groups A and B, while HLA-B*13 was present at a higher frequency in group A. Fewer women in group A carried HLA-A*31, -DRB1*01, and -DRB1*03 genotypes and fewer women in group B carried HLA-B*40 and -DRB1*03 genotypes. Significant differences were found between group B and the control group for HLA-A*11, -B*15, -B*40, and -DRB1*03, and between group A and the control group for HLA-B*15 and -DRB1*12. The HLA-A*11, HLA-B*13, HLA-B*15, and HLA-DRB1*12 genotypes were associated with a higher risk of VLS, while the HLA-A*31, HLA-DRB1*01, and HLA-DRB1*03 genotypes were associated with a lower risk of VLS. In addition, carrying HLA-A*11, HLA-B*15, HLA-B*35, and HLA-DRB1*12 genotypes, and carrying HLA-B*40 and HLA-DRB1*03 genotypes were found to be risk or protective factors for SCHV, respectively.

AB0194 HLA DRB1 alleles in incomplete lupus erithematosus

BackgroundSystemic lupus erythematous (SLE) represents a heterogeneous group of patients. Some of them are diagnosed with SLE with mild articular and cutaneous symptoms, while others present with severe organ damage....

Strategy for the creation of clinical grade hESC line banks that HLA‐match a target population

Here, we describe a pre-derivation embryo haplotyping strategy that we developed in order to maximize the efficiency and minimize the costs of establishing banks of clinical grade hESC lines in which human leukocyte antigen (HLA) haplotypes match a significant proportion of the population. Using whole genome amplification followed by medium resolution HLA typing using PCR amplification with sequence-specific primers (PCR-SSP), we have typed the parents, embryos and hESC lines from three families as well as our eight clinical grade hESC lines and shown that this technical approach is rapid, reliable and accurate. By employing this pre-derivation strategy where, based on HLA match, embryos are selected for a GMP route on day 3–4 of development, we would have drastically reduced our cGMP laboratory running costs.

Blood Group ABO Genotyping in Paternity Testing

Background: The ABO blood groups result from DNA sequence variations, predominantly single nucleotide and insertion/deletion polymorphisms (SNPs and indels), in the ABO gene encoding a glycosyltransferase. The ABO blood groups A1, A2, B and·predominantly result from the wild type allele A1 and the major gene variants that are characterized by four diallelic markers (261G>del, 802G>A, 803G>C, 1061C>del). Here, we were interested to evaluate the impact of ABO genotyping compared to ABO phenotyping in paternity testing. Methods: The major ABO alleles were determined by PCR amplification with sequence-specific primers (PCR-SSP) in a representative sample of 1,335 blood donors. The genotypes were compared to the ABO blood groups registered in the blood donor files. Then, the ABO phenotypes and genotypes were determined in 95 paternity trio cases that have been investigated by 12 short tandem repeat (STR) markers before. We compared statistical parameters (PL, paternity likelihood; PE, power of exclusion) of both blood grouping approaches. Results: The prevalence of the major ABO alleles and genotypes corresponded to the expected occurrence of ABO blood groups in a Caucasian population. The low resolution genotyping of 4 diallelic markers revealed a correct genotype-phenotype correlation in 1,331 of 1,335 samples (99.7%). In 60 paternity trios with confirmed paternity of the alleged father based on STR analysis both PL and PE of the ABO genotype was significantly higher than of the ABO phenotype. In 12 of 35 exclusion cases (34.3%) the ABO genotype also excluded the alleged father, whereas the ABO phenotype excluded the alleged father only in 7 cases (20%). Conclusion: In paternity testing ABO genotyping is superior to ABO phenotyping with regard to PL and PE, however, ABO genotyping is not sufficient for valid paternity testing. Due to the much lower mutation rate compared to STR markers, blood group SNPs in addition to anonymous SNPs could be considered for future kinship analysis and genetic identity testing.

HLA associations with multiple sclerosis in Greece

Multiple sclerosis (MS) is a demyelinating inflammatory disease of the central nervous system originated by a complex interplay of environmental and genetic factors. The association of MS with the human leukocyte antigen (HLA) class II alleles was investigated in MS patients in northwest Greece, in the geographical region of Epirus. Our aim was to estimate the prevalence of the HLA-DRB1*1501, HLA-DQB1*0602 and HLA-DQA1*0102 alleles, consisting the most common susceptibility haplotype in North European and North American Caucasians. We studied 126 MS patients and 93 age and sex matched healthy controls. HLA typing was performed by a polymerase chain reaction (PCR) amplification with sequence-specific primers (PCR-SSP) method. We found that HLA-DRB1*1501, HLA-DQB1*0602 and HLA-DQA1*0102 alleles were significantly more frequent among patients (34% versus 11%, p=0.00015; 69% versus 51%, p=0.01; 76% versus 55%, p=0.002, respectively). HLA-DRB1*1501, HLA-DQB1*0602, HLA-DQA1*0102 haplotype was significantly more common among patients (p=0.00067). HLA-DRB1*1501 and HLA-DQB1*0602 alleles were more frequently detected in patients with initial symptoms from the brainstem or the cerebellum (p=0.024). No significant correlation was observed among these alleles with sex, disease clinical course, or age at onset. This is the first study to investigate genetic susceptibility to MS in Greece. Our results are in line with previous reports in North European and North American patients.

HLA‐A, HLA‐B, and HLA‐DRB1 allele distribution in a large Armenian population sample

Human leukocyte antigen (HLA)-A, HLA-B, and HLA-DRB1 gene frequencies were investigated in 4279 unrelated Armenian bone marrow donors. HLA alleles were defined by using PCR amplification with sequence specific primers (PCR-SSP) high- and low-resolution kits. The aim of this study was to examine the HLA diversity at the high-resolution level in a large Armenian population sample, and to compare HLA allele group distribution in Armenian subpopulations. The most frequently observed alleles in the HLA class I were HLA-A*0201, A*0101, A*2402, A*0301, HLA-B*5101, HLA-B*3501, and B*4901. Among DRB1 alleles, high frequencies of DRB1*1104 and DRB1*1501 were observed, followed by DRB1*1101 and DRB1*1401. The most common three-locus haplotype found in the Armenian population was A*33-B*14-DRB1*01, followed by A*03-B*35-DRB1*01. Our results show a similar distribution of alleles in Armenian subpopulations from different countries, and from different regions of the Republics of Armenia and Karabagh. The low level of genetic distances between subpopulations indicates a high level of population homogeneity, and the genetic distances between Armenians and other populations show Armenians as a distinct ethnic group relative to others, reflecting the fact that Armenians have been an 'isolated population' throughout centuries. This study is the first comprehensive investigation of HLA-allele group distribution in a subset of Armenian populations, and the first to provide HLA-allele and haplotype frequencies at a high-resolution level. It is a valuable reference for organ transplantation and for future studies of HLA-associated diseases in Armenian populations.

Association Between Platelet Endothelial Cellular Adhesion Molecule-1 Polymorphisms and Atherosclerosis: Results of a Study on Patients from Northern Italy

Adhesion of circulating cells to the arterial surface is among the first detectable events in atherogenesis. Cellular adhesion molecules, expressed by the vascular endothelium and by circulating leukocytes, mediate cell recruitment and their transendothelial migration. Platelet endothelial cellular adhesion molecule-1 (PECAM-1), involved in this migration, has been associated with the development of atherosclerosis. Studies have investigated an association between coronary artery disease (CAD) and single-nucleotide polymorphisms (SNPs) located in functionally important domains of the PECAM-1 gene with inconsistent results. Thus, we have analyzed the distribution of V125L, N563S, and G670R SNPs in patients and controls from northern Italy, and also analyzed another functional variant identified in the 5'-untranslated region (UTR) of the PECAM-1 gene (53 G-->A). The polymorphisms of PECAM-1 were genotyped by PCR amplification with sequence-specific primers (PCR-SSP) in 119 controls and 431 CAD patients. Our results demonstrate that genotype and allele frequencies for the 53 G/A polymorphism are significantly different in patients affected by CAD compared to healthy controls, whereas, as regards the V125L and N563S polymorphisms, only the allelic frequency is significantly different. We have shown that there were a significant differences for the 53 G/A and V125L and N563S polymorphisms of PECAM-1 in patients affected by CAD compared to controls. This demonstrates a possible involvement of this gene in contributing to the development of CAD. Therefore, an understanding of the role of the PECAM-1 molecule in this complex mechanism is of pivotal significance in further development of innovative and suitable medical therapies in the future.

Is HLA Matching By SBT A Necessity For BMT?

Hematopoietic stem cell transplantation (HSCT) outcome has improved dramatically since the introduction of allele level HLA typing. Currently, HLA laboratories are using three different technologies for allele level matching, PCR amplification with sequence-specific primers (PCR-SSP), polymerase chain reaction-sequence-specific oligonucleotide probes (SSOP), and sequence-based typing (SBT). However, it is important to emphasize that SBT is the only HLA typing method so far that allows scrutiny of every nucleotide in the HLA gene sequence, therefore, it allows us to recognize new alleles and potential gene mutations that would ensure allele level typing to be as good as claimed.

HLA-B, DR and DQ antigens polymorphism in Tunisian patients with ankylosing spondylitis (a case–control study)

The objective of the study is to assess the distribution of HLA-B genes, HLA-B27 subtypes, HLA-DRB1 and HLA-DQB1 alleles in patients with ankylosing spondylitis (AS) and in control subjects in the Tunisian population and to compare their distribution with that found in other countries. This is a case-control study that included 100 consecutive patients (85 males/15 females) with AS according to the modified New York criteria and 100 control individuals. HLA-B, B27 subtypes and class II (DR and DQ) typing of all subjects was performed by polymerase chain reaction amplification with sequence-specific primers (PCR-SSP). HLA-B27 was found in 62% of patients against 3% in controls (P = 0.0000, OR = 52.6, 15.6 < CI < 166.7). On the other hand, B*07 and B*51 were significantly decreased in comparison with controls (P = 0.01, OR = 0.3, 0.1 < CI < 0.8 and P = 0.0000, OR = 0.2, 0.1 < CI < 0.4, respectively). Eight B*27 subtypes were identified in the AS group, but the most frequent ones were B*2702 (32%) and B*2705 (24%). Among HLA-DRB1 alleles, a significant increase in DRB1*11 was found in comparison with controls (P = 0.01, OR = 2.2, 1.2 < CI < 4.5). However, DRB1*13 had a negative association with AS (P = 0.01, OR = 0.4, 0.2 < CI < 0.8). For HLA-DQB1 alleles, a significant positive association with DQB1*03 was observed in AS group (P = 0.03, OR = 1.8, 1.0 < CI < 3.4). Multivariate analysis by logistic regression revealed that DRB1*11 and DQB1*03 had no direct links with the disease, but were dependent on the presence of HLA-B27. Moreover, B*07 and B*51 seemed to have independently a negative correlation with AS, but DRB1*13 seemed to depend on B*51. Haplotypes carrying B27 were significantly associated with AS and those carrying B*07 or B*51 were negatively correlated with the disease. In conclusion, our study confirms that B27 predisposes to AS while B*07 and B*51 are negatively correlated with the disease.

Analysis of HLA DR2&DQ6 (DRB1*1501, DQA1*0102, DQB1*0602) haplotypes in Iranian patients with multiple sclerosis.

Multiple sclerosis (MS) is prototype of inflammatory demyelinating disease of the central nervous system .The etiology of MS remains unclear, but according to current data the disease develops in genetically susceptible individuals and may require additional environmental triggers. The human leukocyte antigen (HLA) class II alleles (DRB1*1501, DQA1*0102, DQB1*0602) may have the strongest genetic effect in MS. In this study, the role of these alleles were investigated in 183 Iranian patients with multiple sclerosis and compared with 100 healthy individuals. HLA typing for DRB1*1501, DQA1*0102, DQB1*0602 was performed by polymerase chain reaction (PCR) amplification with sequence-specific primers (PCR-SSP) method. The results show that, HLA DR B1*1501 was significantly more frequent among MS patients (46% vs. 20%, PV = 0.0006) but DQA1*0102 haplotype was negatively associated with MS (30% vs. 50%, PV = 0.0049) and no significant association was found with DQB1*0602 and MS patients in comparison with control group (24% and 30%, PV = 0.43). No significant correlation was observed among these alleles with sex, type of disease; initial symptoms, expanded disability status scale (EDSS), as well as age at onset and familial MS. This study therefore indicates that there is no association of above HLA haplotypes with clinical presentation, disease duration, and disability in Iranian patients with MS which is in line with other previous studies in different ethnic groups.

Determination of HLA-B27 subtypes in Iranian patients with ankylosing spondylitis.

The human leukocyte antigen-B27 is one of the class I molecules of the major histocompatibility complex which is strongly associated with ankylosing spondylitis (AS). The strength of the disease association with B27 varies markedly among racial and ethnic populations. It is an allele family, which constitutes about 31 subtypes, with a considerable geographic and ethnic difference in distribution. It is important to know whether certain subtypes show any preferential association with AS. Because there is no report regarding HLA-B27 subtypes in Iranian patients with AS, the main purpose of the present study was to assess the frequency of subtypes of human leukocyte antigen (HLA)-B27 in patients with ankylosing spondylitis in Iranian populationOne hundred and nineteen AS patients (82 HLA-B27 positive and 37 HLA-B27 negative) were selected for this study. HLA-B27 positive patients were screened by polymerase chain reaction amplification with sequence-specific primers (PCR-SSP) for B*27 subtyping.The results of present study revealed that only two subtypes were detected in Iranian patients, including B*2705 (52 patients, 63.4%) and B*2702 (30 patients, 36.6%). Our results showed a restricted number of HLA-B27 subtypes associated with AS in Iran and an elevated frequency of the B*2705 allele in these patients similar to other Euro-Caucasoid (Aryan) groups in the world.

Association of polymorphisms of human leucocyte antigen‐DQA1 and DQB1 alleles with chronic hepatitis B virus infection, liver cirrhosis and hepatocellular carcinoma in Chinese

To investigate whether human leucocyte antigen (HLA) class II DQA1 and DQB1 gene polymorphisms are associated with chronic hepatitis B virus (HBV) infection and development of HBV-related liver cirrhosis (LC) and hepatocellular carcinoma (HCC), we detected the DQA1 and DQB1 allele polymorphisms in 168 HBV carriers (including 48 chronic hepatitis B, 42 LC and 78 HCC patients) and 100 controls who had recovered from HBV infection by using polymerase chain reaction amplification with sequence-specific primers (PCR-SSP). Our data suggest that DQA1*0102 and DQA1*0104 were associated with protection from chronic HBV infection (P(c) = 0.003) and development of LC (P(c) = 0.001), respectively, whereas DQB1*0201 conferred susceptible effect on chronic HBV infection (P(c) = 0.008). We also found that DQA1*0601, DQB1*0601 and DQA1*0201 showed some susceptible effect on chronic HBV infection and LC, respectively, however, these associations were no longer significant after Bonferroni correction (P(c) = 0.390, P(c) = 0.475 and P(c) = 0.140, respectively). No significant association has been found between DQA1 and DQB1 alleles and development of HCC. These results indicate that different subtypes of HLA-DQA1 and DQB1 are associated with development of chronic HBV infection and LC, respectively, in Han Chinese population.

Clearance and Persistence of Hepatitis C Virus in a Tunisian Population: Association with HLA Class I and Class II

Human leukocyte antigens (HLAs) of class I and class II are reported to influence the outcome of hepatitis C virus (HCV) infection. The aim of this study was to assess the role of HLA class I and class II in influencing spontaneous viral clearance or persistence in HCV-infected patients. HLA class I (A and B) typing was performed by lymphocytotoxicity test and HLA class II (DRB1) was determined by low-resolution PCR-SSP (polymerase chain reaction amplification with sequence-specific primers) for 99 subjects (48 men and 51 women). Of these, 75 had chronic infection and 24 had viral clearance. No significant differences were observed between individuals with spontaneous viral clearance or chronic HCV infection for age, sex, source of infection, and risk factors. HLAB-w35 and HLA-DRB1*08 occurred more frequently in those with viral clearance (21.7 and 16.6%, respectively) compared with those with chronic infection (5.5 and 2.6%; p < 0.04 and p < 0.01, respectively). DRB1*15 occurred more often in those with chronic infection (29.3%) compared with those with viral clearance (16.66%), but the difference did not reach statistical significance. These results support the hypothesis that specific HLA class I and class II alleles might influence the clearance or persistence of HCV infection. Both Bw35 and DRB1*08 are associated with clearance of circulating HCV whereas DRB1*15 appears to predispose to progression of liver disease in Tunisian patients. Taken together, our results and those previously reported suggest that HLA associations with the outcome of hepatitis C viremia vary in relation to the ethnicity of the population studied. Further prospective studies of larger cohorts of HCV-infected subjects are needed to evaluate, in different populations, the role of specific HLA class I and class II alleles in the outcome of HCV infection.